This invention relates to a method for determining the optic center of a lens blank, such as an intraocular lens blank or a contact lens blank.
In the manufacture of lenses, the degree of accuracy of alignment of a lens blank to its fixture, e.g., a mandrel, determines the limit of concentricity possible through subsequent machining operations. The fixture is a device that holds the lens blank during multiple processing operations including blocking. A high degree of concentricity is advantageous in the manufacture of lenses since greater concentricity results in less prism. Prior methods of manufacturing lenses relied on mechanical centering for blocking the lens blank. However, mechanical blocking can be slow and inaccurate.
While some attempts have been made to automate this process to some extent, the prior art falls short of achieving the results of the present invention.